As disclosed in one of the present inventors' U.S. Pat. Nos. 6,468,611 and 6,649,236, the problems of cross-infection and the production of antibiotic-resistant mutations have been subjects for concern in hospital settings, as well as in household and other settings, such as the hospitality industry (hotels, motels, bed and breakfast businesses, hostels, etc.). These problems are particularly problematic for those with compromised immune systems or with special bacterial, viral, fungal, parasitic, or other susceptibilities. The latter category of special susceptibilities may also include persons with allergies, and persons who develop one or more of a range of contact dermatitises, to name but a few non-limiting examples.
One way that bacteria, viruses, fungi, and other pathogens are transmitted is by fomites, which are inanimate agents of such transmissions, including, for example, bedding, toilet seats, clothes, table tops and other fixed surfaces, surgical equipment, computer keyboards, etc. Thus, a fomite (also called a fomes) may absorb or otherwise harbor one or more strains of pathogenic bacteria, fungi, viruses, etc., and later transmit those pathogens, by contact, to a human.
A common fomite is bedding, where commonly employed materials, such as cotton, act as wicks to carry pathogens far from the initial contact point with human skin, particularly when moisture is present (sweat, semen, saliva, vaginal secretions, secretions from wounds and open pimples, spilled drinks, etc.). Thus, when sheets and pillow cases are changed, the deeper lying material (mattress, mattress cover, pillow) still harbors potential pathogens of the previous user(s). Furthermore, the next user, particularly when moisture is introduced onto the “scene,” can become infected by reverse wicking; i.e., moisture can draw deep lying pathogens back toward the surface of the bedding that is in contact with the user.
Another common fomite is the surfaces encountered in bathrooms. As has been well documented for decades, toilet seats, the faucet handles of wash basins, door handles, etc., and other surfaces in bathrooms are commonly contaminated with E. coli and other pathogens. As but one illustration of the problem, one need only recognize that a user of a toilet often will leave the toilet with substantial E. coli contamination of at least one hand. That individual may then, in turn, contaminate the knob/handle of the toilet stall, and then one or more faucet handles at a wash basin. Said individual then washes his hands, but touches the one or more faucet handles that he had just contaminated in the process of turning off the water flow, thereby re-contaminating his hand(s). Thus, whatever is subsequently touched by the E. coli-contaminated hand(s) of that individual will also become so contaminated.
As another example of cross-contamination in the bathroom setting, pathogens on toilet seats may be transmittable to the next user. One such example is the herpes viruses, which may be transmitted to a subsequent contactor, particularly if that individual has an open wound. Other pathogens may similarly be so transmitted, though some will require relatively immediate contact by the next person when the pathogen is not hardy outside a “biological” setting (i.e., a setting having the requisite moisture and/or temperature close to human interior body temperature).
Yet another setting that is ripe for cross-contamination is the kitchen. Not only is there the well documented potential problems with contamination sources such as chicken skin (Salmonella, etc.), raw beef (E. coli, etc.), and insects and other bugs and parts thereof (keeping in mind that the FDA allows such contamination to prescribed levels), but also E. coli contamination due to the use of toilets by the kitchen worker (or from contamination by a previous user of the toilet). In the same manner noted above in the context of bathrooms, cross-contamination of faucet handles of wash basins/sinks in kitchens is wide spread. The kitchen cross-contamination problem may also be extended to include problems from the use of cutting boards (problematic particularly with porous material like wood) and from inadequate cooking of contaminated food. In addition, inadequate cleaning of virtually all kitchen surfaces into which human skin comes into contact, directly or indirectly, further compounds the problem of cross-contamination; and this would include not only faucet handles, but also table, counter and other surfaces, as well as handles to ovens, refrigerators, microwave units, etc.
Still another fomite is computer devices where keyboards are used by multiple users in such settings as libraries, computer labs, retail stores and offices. In fact, the Centers for Disease Control traced one norovirus outbreak to computers in a school.
Cross-contamination may also occur during travel. On public transportation such as airplanes, travelers are often provided with complimentary travel pillows. These pillows may have been used by numerous other travelers. Despite changing the outer coverings (which may not occur between flights), these pillows may still harbor pathogens spread by previous users. Similarly, headrests, armrests and cushions of airplane seats may also bear pathogens left by previous users.
U.S. Pat. Nos. 6,468,611 and 6,649,236 to Haskin disclose anti-fomitic devices in the form of a bag or envelope which forms a cover for an object for preventing cross-infection by bacteria and other pathogens that may reside on the object being covered. A sterile inner surface is inverted to form a sterile outer surface. While forming an anti-fomitic barrier when in use, these devices do not prevent future cross-infection from the newly-formed sterile outer surface or from the covered object after removal of the bag or envelope.
The anti-microbial properties of silver (silver ions) have been known for many years. The ancient Romans wrote of the healing powers of silver for treating wounds. More recently, silver nitrate and silver sulphadiazine have been employed topically for the treatment of burns due to the anti-microbial properties of silver. Similarly, silver-coated fibers have been used in surgical, burn, and wound dressings, such as those produced under the Silverlon® brand by Argentum Medical, LLC of Willowbrook, Ill. and the SilverSeal® brand by Noble Biomaterials, Inc. of Scranton, Pa. As such, the anti-microbial properties of silver have, thus far, primarily been used for wound dressings and such. Other similar metals with known anti-microbial properties include copper and zinc.
While the present inventor's U.S. Pat. Nos. 6,468,611 and 6,649,236 to anti-fomitic devices provided a solution to some of the above-mentioned problems, a need still exists for better fitting and adaptability of such anti-fomitic devices to the objects they cover and a way to reduce pathogens on these objects.
In the realm of medical and dental devices that come in direct contact with healthcare workers and patients, as well as in the realm of items common to the household and to the hospitality industry, a need exists for disposable covers that have improved fit and which act in a manner to actively disinfect the items covered to prevent future cross infection. Such covers are sometimes referred to as “drapes.” The covers should be simple in construction, and capable of easy and inexpensive production. The covers should be disposable. The covers should not permit the passage of bacteria and other disease causing organisms (pathogens) to pass from one side to the other. For example, organisms on a medical device should not be able to come in contact with a patient or healthcare worker, and, likewise, organisms on or in a patient or healthcare worker should not be able to penetrate the covers and thereby contaminate medical devices protected by the covers. Furthermore, the covers should have sufficient anti-microbial properties to kill a substantial portion of bacteria, fungi, and viri existing on the surface of the object covered and on the outer surface of the cover.
With respect to bedding and other applications (e.g., covers for equipment, faucet handles and other handles, etc.), the covers similarly should not permit the passage of pathogens from one side of the covers to the other. The covers preferably employ silver or the like (e.g., copper, zinc, etc.) in a manner sufficient to impart anti-microbial properties and should also be non-reactive with typical human skin so as not to produce irritation or contact dermatitis. The covers should be capable of easy and quick application for covering the desired object. Finally, the covers should be easily sealable or attachable, where applicable.